This invention relates to apparatus and method for producing products composed of flexible sheet material having elastic portions tending to contract the product during manufacture, and more particularly to apparatus and method which maintains the sheet material in stretched condition during assembly and produces appropriate folding, sealing, tucking and other desired operations thereon.
In the production of products manufactured of flexible sheet material, such as in the manufacture of disposable absorbent garments, it is often difficult to control the orientation of the flexible sheet material as it moves through the manufacturing process. In many instances, it is necessary to maintain the sheet material substantially planar while various operations are exercised upon it.
This difficulty in maintaining control of the sheet material becomes even more pronounced when elastic members are a part of the product. For example, in the production of disposable absorbent garments such as diapers or training pants, elastic members are secured to the sheets extending transversely thereof to provide fitted waistbands, and longitudinally extending elastic elements are attached to provide form-fitting leg cuffs in the garment.
In the past it has been difficult to maintain such products in a stretched substantially planar orientation as the products are carried along a path during the manufacturing operation due to the tendency of the elastics to contract the product. Further, problems have existed in holding the sheet material and product in proper orientation during operations to produce needed folding, joining, trimming with movement of the product along a conveying path to produce a finished product.